The answer is YES. Aa switch acting as a VTP server could come online with a higher configuration revision number and can replace all vlan configurations with its own higher revision number configs. But the same can be done by a switch acting as a client and powers up with a higher revision!
If you planning to upgrade your graylog and want to see what your graylog current version is, here is how you can check it. Go to the Graylog Web Interface Click on System/Nodes Under System/Nodes --- Click on the N odes Scroll down to the ' System ' Here you can see the current version of your graylog server